The present invention relates to a cigarette manufacturing unit.
More specifically, the present invention relates to a manufacturing unit at least partly defining a cigarette manufacturing and processing line, and comprising a first machine with two outputs for substantially similar streams of cigarettes; two second machines with respective inputs; and two bulk cigarette conveyors, each connecting a respective output of the first machine to the input of a respective second machine.
The present invention may be applied to advantage to manufacturing units of the above type, and in particular of the type described and illustrated in Italian Patent Application n. BO92A 000311 wherein said first machine consists of a filter assembly machine supplied by a manufacturing machine with a stream of double cigarette portions. According to the above patent application, each double cigarette portion is cut in half into two coaxial single portions which are parted for inserting a double filter to which the single portions are joined by means of a connecting strip to form a double cigarette. The double cigarettes so formed are then cut in half to form two streams of single cigarettes, which are fed to respective outputs of the filter assembly machine. The cigarettes in the two streams are oppositely oriented, and may be oriented the same way by turning over the cigarettes in one of the streams either upstream from the respective output, as in the above patent, or in known manner downstream from the output.
According to the above patent application, the cigarettes at the two outputs are transferred to the inputs of respective independent packing machines by means of respective bulk conveyors.
In the above known manufacturing unit, though substantially similar, the two streams of cigarettes supplied to the packing machines may differ slightly, due to different numbers of cigarettes in each stream being rejected on the filter assembly machine; and, though normally set to the same output rate, the two packing machines may also reject different numbers of cigarettes, thus resulting in a different throughput on each machine.
When combined, both the above factors may result in one of the bulk conveyors being emptied and so arresting both its own and the other packing machine, due to both streams of cigarettes being linked, and nonthroughput on either one of the two bulk conveyors resulting in immediate stoppage of the filter assembly machine.
The same also applies in the event the above manufacturing unit is replaced by a similar unit for producing and processing plain cigarettes, and wherein the filter assembly machine is replaced, for example, by a dual-rod cigarette manufacturing machine.